In recent years, a large capacity inverter apparatus expands its application, and is widely used mainly in an industrial field. In the case of a large capacity inverter apparatus, it is important to improve its overall efficiency, and accordingly, an output voltage is made high, and thereby the total loss including the loss of wiring such as a cable is reduced. In addition, as an inverter apparatus with a high voltage output like this, an apparatus is used in which a plurality of inverter apparatuses are multiplexed, and it is common to improve an output waveform using so-called pulse width modulation control.
As an example of this, a multiple inverter apparatus in which a single-phase inverter is connected in series with each phase of a three-phase inverter has been proposed (Refer to Patent Document 1, for example.).